Answer
D.Diffraction
Explanation
Diffraction is a property that is experienced by waves when they come across a barrier when they are in motion.
The ways tends to curve behind the barrier. This is called diffraction of waves.
Now, sound is a wave and it also experience diffraction. . So the brother will be able to hear the sound due to diffraction
Answer:
Sound wave types - longitudinal waves
Longitudinal waves - Vibrating string the creates sound in the way it moves.
Explanation:
Longitudinal waves have particles of the medium that are displaced in a parallel direction to energy transport.
For any mass m:
a = F/m
v = √2*F/m*s = √2F/sm = k/√m
Momentum = mv = k√m
Energy = 1/ mv² = 1/2 m.k²/m = 1/2k²
SO
Both will have same energy
The larger mass will have greater momentum
Solution :
We know, resistance is given by :


Now, we know mass of wire is given by :

Hence, this is the required solution.